1. Field of the Invention
The present invention relates to optical disc recording and reproducing apparatuses, and in particularly, to an optical disc recording and reproducing apparatus having a function of communicating with a noncontact integrated circuit (IC).
2. Description of the Related Art
As media capable of recording a large amount of data, various optical discs, such as read only memory (ROM) media, recordable media, and rewritable media, are becoming widespread.
Radio frequency identification (RFID) for authentication by noncontact communication is known. A noncontact IC card used in the RFID has the following features: Since communication between a noncontact IC chip and a data reader/writer is achieved without physical contact therebetween, processing time from the start of communication connection to the end thereof is short. The use of high-grade encryption and mutual authentication provide high-level security. Accordingly, noncontact IC cards each having an electronic money function are becoming widely available.
A recording medium including a noncontact IC chip and an optical disc on the same substrate is known as a medium having the combination of the features of the above-described optical disc and noncontact IC chip.
For example, Japanese Unexamined Patent Application Publication No. 8-161790 (Patent Document 1) discloses an optical disc mounting a noncontact IC chip. This chip is arranged in a central portion of the optical disc, i.e., on the periphery of a center hole through which a rotating shaft is inserted.
Japanese Unexamined Patent Application Publication No. 9-245381 (Patent Document 2) discloses an optical disc including two substrates. In this disc, a circuit unit and a coil unit are arranged in a clearance between recesses of the two substrates.
Japanese Unexamined Patent Application Publication No. 11-353714 (Patent Document 3) discloses an optical disc in which a reflecting film of the optical disc and an antenna coil of a noncontact IC chip are made of the same material by vapor deposition and sputtering.
Japanese Unexamined Patent Application Publication No. 2001-319380 (Patent Document 4) discloses an optical disc including a noncontact IC chip and an antenna coil arranged in a region between a lead-in area of the optical disc and the inner periphery thereof. In this optical disc, a notch is formed on a reflecting film in the vicinity of the inner periphery in order to avoid a phenomenon in which a communication distance is reduced by the reflecting film near the inner periphery because the IC chip and the antenna coil are disposed on the reflecting film. The notch reduces an effect on electromagnetic induction produced by the antenna coil.
Further, there is known an optical disc recording and reproducing apparatus compatible with the above-described recording media each including a noncontact IC chip and an optical disc on the same substrate. The apparatus has an optical-disc recording and reproducing function and a communication function of communicating with a noncontact IC chip. For example, Japanese Unexamined Patent Application Publication No. 2001-297568 (Patent Document 5) discloses such an apparatus including an internal antenna and an external antenna. Those antennas are connected in parallel to radio frequency circuits, respectively. The apparatus is capable of communicating with noncontact IC chips which are close to the respective antennas.